#include<stdio.h>
#include<ctype.h>
int main()
{
    int i = 0;
    char str[] = "Hello Laura.\n";
    char ch;
    while(str[i])
    {
        ch = str[i];
        if(islower(ch))
            ch = toupper(ch);//小写转大写，还有 tolower()大写转小写

        putchar(ch);
        i ++;
    }
    return 0;
}